1. Field of the Invention
The invention relates to wells and particularly to water wells, and to an improved method of cleaning water wells and the apparatus used therefor. More particularly, the invention relates to a method which produces a pulsating action at the lower end of the well casing to unblock the inlet openings of the well casing and for rejuvenating the surrounding strata by the repetitious creation and destruction of a vacuum in the well casing which raises and discharges a column of water therein.
2. Description of the Prior Art
Usual water well systems consist of a well casing which is formed of a plurality of interconnected lengths of pipe which are placed in a bore hole and extend into the ground and terminate in the water-bearing strata a certain distance below the ground level. The bottom section of the wall casing is provided with a screen, perforated section of pipe or other structure having a plurality of holes through which the water from the surrounding strata flows into the well casing to create a water pool therein. A submersible pump may be located in the bottom of the well and attached to a delivery tube which extends upwardly therefrom toward the surface for removing the water therefrom. Alternately, a pump may be located on the surface above the well for drawing water upwardly through the delivery tube from the water pool in the lower end of the casing.
A bed of gravel and sand is formed about the inlet end of the well casing and filters the water as it flows into the casing and also prevents the flow of foreign materials and other objects through the holes and into the well casing. Over a prolonged period of time, these inlet openings become partially blocked by smaller particles of silt, sand and gravel, and become coated with encrustations formed by the various minerals present in most water-bearing strata. This blockage of the inlet holes will reduce the rate of flow of water into the well casing and, correspondingly, the amount and rate of water flow that can be obtained therefrom at a house or building on the ground surface. Likewise, the strata become clogged in the area which surrounds the casing inlet end, further reducing the flow of water into the well casing for subsequent delivery to the upper ground level.
Various devices and equipment have been devised to rejuvenate or clean a well by unblocking the inlet openings and by regenerating the surrounding strata to increase the flow rate of water into the well casing. For example, various types of cleaning systems apply a high pressure on the water in the well casing by a pump which forces the water outwardly through the inlet openings at the lower end of the well and into the surrounding strata to unblock and rejuvenate the same. Examples of such positive pressure well cleaning systems are shown in U.S. Pat. Nos. 647,951, 1,576,538, 1,642,245, 1,774,640, 2,120,132 and 2,768,694.
Other cleaning systems use mechanical devices placed within the well casing to create a sudden surge of liquid pressure outwardly through the screen such as by a piston or plunger, as shown in U.S. Pat. No. 1,488,662. Other systems lower bailers or other receptacles into the bottom of the well for scraping the inside of the casing for removing trapped particles, such as shown in U.S. Pat. No. 1,597,180. Still other systems apply an unblocking pressure by means of frozen carbon dioxide particles which are dropped into the well and upon transformation increase the pressure in the well, forcing the trapped water out through the openings and into the surrounding strata to clean and rejuvenate the same. Examples of these dry ice cleaning methods are shown in U.S. Pat. Nos. 1,843,002 and 2,811,209.
Also, in other well cleaning systems, various chemicals are placed in the well casing for reacting with the strata and encrustations on the inlet pipe section for dissolving the mineral deposits, such as shown in U.S. Pat. Nos. 1,999,146 and 2,850,098. Still other well cleaning systems develop a pulsating action at the inlet end of the casing by applying and removing a positive pressure to the well for pumping the water outwardly and inwardly through the openings for unclogging the same and for rejuvenating the surrounding strata, such as shown in U.S. Pat. Nos. 2,354,570, 2,768,694 and 2,907,390.
Although some of the particular methods and apparatus known in the art may be satisfactory for cleaning and rejuvenating a well, they have one main disadvantage and drawback. Most of these systems require expensive and cumbersome equipment which must be placed into and extend throughout the length of the well after the well delivery tube and pump have been removed therefrom. The removal of the existing delivery tube and/or pump from a well is time consuming and expensive, as is the placement of special equipment into the well which is required for cleaning and rejuvenating the well. Also, these prior art methods require large pumps and power supplies for creating the desired amount of pressure for forcing the water outwardly through the screen openings and into the surrounding strata.
Thus, the need has existed for a well cleaning method and apparatus which does not require the removal of the existing water delivery tube and submersible pump from withoin the well casing, and in which the cleaning is accomplished with relatively lightweight, inexpensive, and portable equipment. There is no known system and apparatus of which I am aware which accomplishes these results other than my particular invention which is described and set forth more fully below.